Gardening and Mental Health: A Brief Overview

People around the world use gardening to interact with nature

Gardening is one of the most popular ways in which people interact with nature globally. It is estimated that in the U.S., 1 in 3 adults (almost 120 million) engage in gardening as a hobby on a regular basis. The numbers are similar in other countries where surveys of gardening have been done, including Japan (32 million or 1 in 4), the U.K. (23 million representing almost 90 percent of households), as well as New Zealand and Sweden.

Established beneficial effects on physical and mental health

The World Health Organization (WHO) defines health as “a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity.” Good health includes physical, psychological, and spiritual well-being. There is substantial evidence that frequent contact with natural environments has beneficial effects on both physical and mental health, including reduced risk of diabetes, heart disease, enhanced longevity, and for our interest today, lessening symptoms of stress, depression, and anxiety.

Regular gardening has also been shown to enhance overall life satisfaction, general well-being, cognitive function, and community engagement. The medical profession acknowledges that regular contact with nature, including spending time outdoors working in a garden, is a cost-effective, preventive therapy. For all of these reasons "horticultural therapy" is now widely recommended for a variety of medical and mental health problems. Horticultural therapy entails the engagement of a person in gardening or other plant-based activities, facilitated by a trained therapist to achieve specific goals, such as lessening a depressed mood, enhancing stress management skills, and improving the overall quality of life.

Gardening enhances the overall quality of life and decreases the severity of depression, anxiety, and other mental health problems

A 2017 meta-analysis identified 21 English language studies on health outcomes related to gardening published in peer-reviewed journals between 2001 and 2016. Gardening types examined included daily gardening and short-term gardening. Eleven studies focused on patients with serious mental health problems, such as major depressive disorder and Alzheimer’s disease. Eleven studies focused on the benefits of gardening in individuals without serious medical or mental health problems.

The authors found that participating in gardening activities reduced the severity of depressed mood and anxiety, reduced stress, and enhanced overall quality of life. Another significant finding was a cumulative positive effect on mental health from repeated short-term engagement in gardening activities. No significant differences in outcomes were found with respect to differences in the socio-economic status of gardeners. Three studies included in the analysis showed that even short-term involvement in gardening (e.g., several hours) led to rapid improvements in symptoms of depressed mood and anxiety; however, it wasn’t clear how long such improvements lasted.

Individuals participating in horticultural therapy experienced more significant improvements than individuals who engaged in gardening activities in a less structured way, and these improvements continued three months after therapy had ended. Multiple causal mechanisms may help explain relationships between gardening and improved physical and mental health, including general health benefits of direct contact with nature, which may be "cognitively restorative" and may result in "restoration of attention fatigue."

In addition, maintaining a garden encourages people to exercise on a regular basis, which has established physical and mental health benefits. Gardening provides opportunities for increased community engagement reinforcing social ties. Finally, the beneficial effects of gardening may be associated with a healthier diet that results from consuming home-grown vegetables and fruits high in nutrient content.

A different systematic review published in 2020 in the British Medical Journal on the impact of gardening on health and well-being included 77 studies conducted in the U.S., the UK, Brazil South Korea, Taiwan, Japan, and the Netherlands. Studies investigated interventions ranging from viewing gardens and taking part in gardening activities to engaging in horticultural therapy. Seventeen studies examined the benefits of horticultural therapy in which a structured gardening program is done in conjunction with individual therapy.

Engagement in gardening activities was found to reduce stress, improve depressed mood, and strengthen social engagement. These findings confirmed the findings of the 2017 review (above), including the positive impacts on overall physical health and emotional well-being. The authors suggested that clinicians should "prescribe" gardening for both the prevention and treatment of a range of physical and mental health problems.

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Gardening may play an even more important role during COVID-19

As I write, we are in the 8th month of a global pandemic. It is likely that a large percentage of the world's population will eventually be infected with COVID-19, resulting in potentially severe health and mental health consequences. Chronic exposure to stresses caused by the pandemic among countless millions constitutes a "perfect storm" with on a global scale including increased rates of depressed mood, suicide, and post-traumatic stress disorder.

The crisis is being made worse by the widespread disruption in social support networks during prolonged periods of enforced social distancing. Individuals who were already struggling with mental illness before COVID-19 are now facing even greater challenges. These circumstances may worsen in the context of widespread poverty and hunger, entrenched disparities in health care among minorities and the underserved, and an overall decline in access to health care resulting from the economic breakdown in the wake of COVID-19 (Ahonen, Fijishiro, Cunningham and Flynn 2008).

A systematic review of studies on the mental health consequences of the COVID-19 pandemic published in May 2020 included 43 studies. Two studies investigating COVID-19 patients found that over 96 percent of patients who survived critical illness related to COVID-19 met the criteria for PTSD. Patients diagnosed with or recovering from COVID-19 had a significantly higher risk of depressed mood, suicide, anxiety, insomnia, and substance abuse.

Patients with preexisting psychiatric disorders reported worsening of their symptoms. Health care workers who treat patients infected with COVID-19 likewise reported high rates of depressed mood, anxiety, chronic stress, and poor sleep quality. Studies included in the review on the mental health impacts of the pandemic on individuals who were not infected with SARS-CoV2 revealed lower general psychological well-being and higher scores of anxiety and depression compared to before COVID-19.

Bottom line

Hundreds of millions of people engage in gardening and other nature-based activities in all world regions. Regular gardening has established beneficial effects on general physical health and well-being and reduces the severity of depressed mood, anxiety, and other specific mental health problems. The serious, widespread mental health consequences of the COVID-19 pandemic provide even more reasons to engage in gardening for health and well-being than during normal times.